Double-valve construction



May 6, I924. 1 1,493,149

LE 'ROY 'H. CRANDALL I I DOUBLE VALVE CONSTRUQHON Filed April .1. 1925 Invemon Lefioy Hfircmdmll Patented May 6, 1924.

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DOUBLE-VALVE CONSTRUCTION.

Application filed April 11, 1923. Serial No. 631,286.

T 0 all whom it may concern Be it known that 1, Ln ROY H. CRANDALL, a citizen of the United States, and resident of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Double-Valve Construction, of which the following description, in connection with the accompanying drawing, is a specification,

like characters on the drawing representing g oline reservoir and to. stand n said reservolr.

like parts. I v

This invention relates to a valve construction and the object thereof. is to providea double check valve for use in a fluid conveying pipe to prevent the passage of fluid in one direction through said pipe and permit the passage of fluid in the other direction.

One of the objects of the present invention is more particularly to provide a double check valve in which the lower valve forms a guide for the stem of the upper valve.

A further object of the present invention is to provide adouble check valve in which the guides for the stems of both valves are below their respective valve seats.

A further object of the present invention is to provide a valve construction for a double check valve in which a part integral with the casing forms-a guide for the stem of the lower valve. 7 l

A further object of the present invention is to provide a double check valve in which the valves are so arranged that the raising of-the lower valve assures the raising of the upper valve. h

A further object of the present invention is to-provide a double check valve having means to retain the upper valve within the valve casing when said valve is raised.

Other objects and features of the inven: tionwill more fully appear from the following description and accompanying drawings and will be particularly pointed out in the claims.

The drawings illustrate both in elevation and section a preferred form of valve construction and embody the broad, principles of the invention.

In the drawings: 7 Fig.1 is an elevation of the valve casing;

Fig. 2 is a sectionfrom top to bottom through. th valve assembly showing parts of the valve in elevation; j

Fig. 3 is a section on line w-w Fig. 2, the valves being? removed;

'1 extended at 13.

Fig. {L is a section on line a:w Fig. 2, the valves being in place- The valve construction illustrated herein is designed to be used in a fluid-conveying pipe, particularly in the pipe which leads from the reservoir to the pump of a gasoline filling station. The valve construction shown 7 in the drawings is intended to be placed on the bottom of the pipe leading from the gas- In the valve construction illustrated the guidesfor both valves are below the valve headsto insure that the valve always seats properly toprevent theba'ckward flow .of gasoline in theres'ervoir, and the valves are so arranged that the lower valve co-operates V with the upper valve to assure the raising of the upper valve.

As :illustrated herein a preferred form of device constituting the invention consists of a casing lhaving therein an upper and a lower valve 2 and 3 respectively and a web 4: located below thelower valve. The web 4: is formed integral with the casing 1 and has" a vertical guide opening 5 therein located directly below the. center of the lower valve seat 6. p

The lower valve has a stem 7 depending therefrom which co ope'rates. with the guide opening inthe web to insure that the head 8 of the lower valve properly seats. The lower valve stem has means thereon for'retaining i the end of the stem alwaysbelowthe web. To obtain" this the end of thelower valve stem is reduced 'andthreaded at 9 and a retaining meansfsuch as a nutlO is placed thereon. An opening may conveniently be formed through the nut and the reduced end 9 of the lower valve stem and a cotter pin 11 placed therethrough to prevent the nut from becoming loosened to retain the nut on the endfof'the valve stem.

A vertical guide recess l2extends through the head of .the lower valveand into the valve stem to form a guide for the stem of the upper valve. The recess may be of any desired depth but it is obvious that it. shouldbe of such a depth that'it will give .such guidance to the stem of the upper valve as to insure theproperseating of said valve and in order to providea recess of the required depth the lower valve head has been The upper ,valve'consistsofa valve seat let'and valve head 15' from which depends a valve stem 16 or" such a length that when both valves are seated it extends nearly to the bottom of the guide recess 12 in the lower valve as is clearly shown in Fig. 2 of the drawings. The upper valve stem 16 is ex tended in this manner so that should the upper valve stick before it has risen to the proper height the end of the stem will come in contact with the bottom of the recess 12 as the lower valve rises, and the lower valve will carry the upper valve with it to such a height that the gasoline will easily fiow around both valves. The upper valve is retained within the casing by means of a bar 17 which extends across the head, of the valve and parallel thereto. A threaded boss 18 extends upwardly from the center of the upper valve and the bar 17 is placed on the threaded boss and retained in place by a screw 19 which screws into the threaded boss 17. The bar is of such alength that it extends nearly to the walls of the casing.

The casing 1 which incloses the valve is formed in a single piece and the upper and lower valve seats let and 6 respectively and the web 4 are formed integral therewith. The valve seats are spaced from the walls of the casing as shown in order that they will not be distorted when the casing is screwed onto the end of the pipe which leads from the reservoir to the gasoline pump. In order that both valves may be easily placed in and removed from the casing, the upper valve seat and its associated valve head are larger than the lower valve seat and the lower valve head so that in assembling the valve construction the lower valve head is put into the casing and through the upper valve seat down on the lower valve seat.

The upper end 20 of the casing has an opening therethrough which is of smaller diameter than the inside of the casing to form a shoulder 21 around the inner end of said opening. This opening may be threaded for connection with the end of the fluidconveying pipe leading to the pump. The bar 17 is longer than the diameter of this opening so that the upper valve is retained within the casing when said valve is raised by the extremities of the bar contacting with said shoulder.

The lower end of the casing has openings 22 therein. which when formed leave supports 23 connecting the main body of the casing with they extreme lower end. 24; thereof. A strainer 25, preferably a cylin-= drical screen, closes the openings 22 in order to keep any solid matter out of the valve assembly. This strainer 25 is retained in position by having its upper end seated in grooves 26 cut in the web 4 and its lower end abutting a cap 27 which is retained on the extreme lower end 24 of the casing by means of co-operating threads 28 cut both on the casing and on the cap.

The entire valve assembly may be made of any suitable material. It has been found that brass is such a material because it can easily be cast to form the casing and valves and then easily worked to form the valves and valve seats which, it is obvious, must be very accurately ground since gasoline will leak quite rapidly around a valve head which is inexactly seated. It will thus be seen that the valve construction described herein is extremely simple to make and the proper operation of the valves is assured.

Having thus described the invention, what is claimed'as new anddesired to be secured by Letters Patent, is:

1. A valve constructlon comprising a single casing having integral therewith a lower valve seat and an upper valve seat larger than said lower valve seat and. a

web located. below the lower valve seat, the.

web having a vertical guideopening therein located directly below the center of said lower seat, a lower valve with a head of a size to pass through the upper valve seat and to fit the lower valve seat, a stem depending from said head co-operating with the guide opening in said web, a vertical guide recess extending through said head into the valve stem, and an upper valve with a head fitting the upper valve seat and a stem co-operating with the guide recess, whereby a part integral with the casing forms a guide for the stem of the lower valve and the lower valve forms a guide for the stem of the upper valve and the guides for both, valves are below-their respective valve seats.

2. A valve construction comprising a casing having therein an upper and a lower valve seat and a web located below'the lower valve seat, the web having a vertical guide opening therein located directly below the center of said lower seat, a'lower valve with a head fitting the lower valve seat, a stem depending from said head co-operating with the guide opening in said web, a vertical guide recess extending through saidhead into the valve stem, and an upper valve with a head fitting the upper valve seat and a stem extending nearly to the bottom of said guide recess when both valves are seated,whereby the lower valve forms a guide for the stem of the upper valve and assures the raising of the upper valve when the lower valve'is raised and the guides for both valves are below their respective valve seats.

3. A valve constructioncomprising a casing having therein an upper and a lower valve seat spaced from the inner walls of the casing and a web located below the lower valve seat, the upper end of the casing having an opening therethrough of a smaller diameter than the inside of thecasing to form a shoulder around the inner end of said opening and the web having a verco-operating with the guide opening in said web, a vertical guide recess extending through said head into the valve stem, an

upper valve with a head fitting the upper valve seat and a stem co-operating with the guide recess, and a bar longer than the diameter of the opening through the upper end of the casing removably fastened to the upper valve head and parallel therewith, whereby the lower valve forms a guide for the stem of the upper valve and the guides for both valves are below their respective valve seats and the upper valve is retained within the casing when said valve is raised by the extremities of said bar contacting with said shoulder.

In testimony whereof, I have signed my name to this specification.

LE ROY H. CRANDALL. 

